Air-speed indicator



C. R. COLT.

AIR SPEED INDICATOR. APPLICATION FILED JUNE 16, 1920.

Patented Nov. 21, 1922.

25 the wing fabric, an expensive 45 through small atented Nov. 21, 1922.

CHARLESR. COLT, F WASHTNGTON, DISTRICT OF COLUMBIA.

AIR-SPEED mnroa'ron.

Application filed June 16, 1920. Serial No. 389,440.

To all whom-it may concern:

Be it known, that I, CHAnnns R. Cour, a cltlzen of the United States,residing at Washington, District of Columbia, have invented certain newand useful Improvements in Air-Speed Indicators, of which the followingis a specification.

My invention relates to aircraft and particularly to means foraccurately indicating the speed of travel or flight of such craftthrough the air.

Heretofore, speed indicators for aircraft have depended, in most of thedevices in actual use, upon air pressure, or air trapped a funnel likereceiver, for example, and conducted through tubing to an indicatoractuating element such as a bellows. Repair work on such an appliancehasbeen found diflicult, as, ordinarily, such tubing is housed in one ofthe wings or planes between the fabricsurfaces thereof and being'comparatively inflexible, the removal and replacement of the tubing hasnecessitated the removal and replacement of a large section-of andtime-consuming operation. Furthermore,

down and assembling an airplane, such tubing is frequently bent, mashedor otherwise injured, resulting in rendering the speed inin taking 80dicator of little value and practically unreliable.

a The object of this invention is to produce a speed indicator foraircraft embodying a small air driven propeller (screw), an electriogenerator directly driven thereby and preferably 0 streamline formationto minimize head resistance, said elements to be disposed in the airstream line, indicating means embodying an eleotro-magnet, and

flexible current-conducting means connecting said generator and magnet.The wires forming easily strung through or otherw se placed 1n the wingor 1plane, passing 1n and out oles in the fabric, thus saving much laborand time and insuring the working efliciency of the speed indicator.

The invention consists'inlthe constructlon, combination and described,illustrated and claimed.

The accompanying drawing raphically illustrates the complete speed inlcator applied to an airplane.

The speed indicator as a whole, comprises. an electric'generator A, anindicator B, and

electric conductors C, connecting the genertension arm 15 of thepointer.

said conducting means may be,

nism above descrlbed.

arrangement herein fully to the coil 8 of the magnet D and the armaatorwith an electro-magnet D in the casing of the indicator B. i

The generator A comprises a casing a of streamline formation, as shown,the same being illustrated as mounted on one of the struts 1 connectingthe top and bottom planes 2 and 3 respectively of a'biplane structure.The shaft 4 of the generator has directly mounted thereon an air-drivenpropeller (screw), 5, facing forwardly and serving to drive thegenerator, the generating speed of which varies according to the speedof travel of the aircraft in actual flight as well as when rollin on theground prior to any in motion.

The indicating mechanism is housed in a casing 6 and comprises a pivotedand swinging indicating hand or pointer 7 controlled and actuated by theelectro-magnet D, the latter being shown as a solenoid having a coil 8and sliding core or armature 9. The

PATENT OFFICE.

taking off or after anding. The generator, including the propeller maybe mounted on' part of the aircraft where it will be exposed to the airstream while the craft is terminals of the coil 8 are fastened tobinding posts 10 which are attached the con- I ductors C. v

The pointer 7 is coupled or linked to the armature 9 by ny suitabletransmission means such as a lever 11 mounted on the pivot pin 12 of thepointer 7, said lever having a stud 13 working in a slot 14 in an ex-The lever 11 has a curved slot 16 in which'works a pin or stud 17 on thearmature 9.- A spring 18 holds the pointer 7 normally at zero butpermits it to traverse a graduated scale 19 consisting of an arcuatecalibrated plate visible through. a glazed opening 20 in'the casing-6.Another glazed opening 21 gives a view of the working parts of themecha- As the generator is driven it generates electric energy inproportion to the speed attained, such speed, in'turn being governed byand in accordance with the 'rate of travel ofthe aircraft in flight. Thecurrent thus generated is transmitted through-the wire C cates in milesper hour or other measurement the rate of travel of the aircraft throughthe The mechanism of the complete apparatus is simple and reliable inoperation, and enables the indicator as a whole to be quickly mounted inposition and unmounted for recomprising, in combination, an indicator, asolenoid magnet, a swinging indlcator hand, a motion transmlttlng leverconnecting said hand with the armature of the solenoid magnet, agenerator driven by an air-driven propeller, and electrical conductorsextending from the generator'to the coil of the solenoid magnet.

In testimony whereof I have affixed signature.

- CHAS. R. GOLT.'.

